bgpd: prefix-sid srv6 l3vpn service tlv

bgpd already supports BGP Prefix-SID path attribute and
there are some sub-types of Prefix-SID path attribute.
This commits makes bgpd to support additional sub-types.
sub-Type-4 and sub-Type-5 for construct the VPNv4 SRv6 backend
with vpnv4-unicast address family.
This path attributes is already supported by Ciscos IOS-XR and NX-OS.

Prefix-SID sub-Type-4 and sub-Type-5 is defined on following
IETF-drafts.

Supports(A-part-of):
- https://tools.ietf.org/html/draft-dawra-idr-srv6-vpn-04
- https://tools.ietf.org/html/draft-dawra-idr-srv6-vpn-05

Signed-off-by: Hiroki Shirokura <slank.dev@gmail.com>

bgpd/bgp_attr.h

@@ -62,12 +62,15 @@
 #define BGP_PREFIX_SID_LABEL_INDEX     1
 #define BGP_PREFIX_SID_IPV6            2
 #define BGP_PREFIX_SID_ORIGINATOR_SRGB 3
+#define BGP_PREFIX_SID_VPN_SID 4
 #define BGP_PREFIX_SID_SRV6_L3_SERVICE 5
 #define BGP_PREFIX_SID_SRV6_L2_SERVICE 6
 
 #define BGP_PREFIX_SID_LABEL_INDEX_LENGTH      7
 #define BGP_PREFIX_SID_IPV6_LENGTH            19
 #define BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH  6
+#define BGP_PREFIX_SID_VPN_SID_LENGTH         19
+#define BGP_PREFIX_SID_SRV6_L3_SERVICE_LENGTH 21
 
 #define BGP_ATTR_NH_AFI(afi, attr) \
 	((afi != AFI_L2VPN) ? afi : \
@@ -111,6 +114,29 @@ enum pta_type {
 	PMSI_TNLTYPE_MAX = PMSI_TNLTYPE_MLDP_MP2MP
 };
 
+/*
+ * Prefix-SID type-4
+ * SRv6-VPN-SID-TLV
+ * draft-dawra-idr-srv6-vpn-04
+ */
+struct bgp_attr_srv6_vpn {
+	unsigned long refcnt;
+	uint8_t sid_flags;
+	struct in6_addr sid;
+};
+
+/*
+ * Prefix-SID type-5
+ * SRv6-L3VPN-Service-TLV
+ * draft-dawra-idr-srv6-vpn-05
+ */
+struct bgp_attr_srv6_l3vpn {
+	unsigned long refcnt;
+	uint8_t sid_flags;
+	uint16_t endpoint_behavior;
+	struct in6_addr sid;
+};
+
 /* BGP core attribute structure. */
 struct attr {
 	/* AS Path structure */
@@ -198,6 +224,12 @@ struct attr {
 	/* MPLS label */
 	mpls_label_t label;
 
+	/* SRv6 VPN SID */
+	struct bgp_attr_srv6_vpn *srv6_vpn;
+
+	/* SRv6 L3VPN SID */
+	struct bgp_attr_srv6_l3vpn *srv6_l3vpn;
+
 	uint16_t encap_tunneltype;		     /* grr */
 	struct bgp_attr_encap_subtlv *encap_subtlvs; /* rfc5512 */
 

bgpd/bgp_memory.c

@@ -128,3 +128,6 @@ DEFINE_MTYPE(BGPD, BGP_FLOWSPEC_RULE_STR, "BGP flowspec rule str")
 DEFINE_MTYPE(BGPD, BGP_FLOWSPEC_COMPILED, "BGP flowspec compiled")
 DEFINE_MTYPE(BGPD, BGP_FLOWSPEC_NAME, "BGP flowspec name")
 DEFINE_MTYPE(BGPD, BGP_FLOWSPEC_INDEX, "BGP flowspec index")
+
+DEFINE_MTYPE(BGPD, BGP_SRV6_L3VPN, "BGP prefix-sid srv6 l3vpn servcie")
+DEFINE_MTYPE(BGPD, BGP_SRV6_VPN, "BGP prefix-sid srv6 vpn service")

bgpd/bgp_memory.h

@@ -126,4 +126,7 @@ DECLARE_MTYPE(BGP_FLOWSPEC_COMPILED)
 DECLARE_MTYPE(BGP_FLOWSPEC_NAME)
 DECLARE_MTYPE(BGP_FLOWSPEC_INDEX)
 
+DECLARE_MTYPE(BGP_SRV6_L3VPN)
+DECLARE_MTYPE(BGP_SRV6_VPN)
+
 #endif /* _QUAGGA_BGP_MEMORY_H */

bgpd/bgp_route.c

@@ -38,6 +38,7 @@
 #include "workqueue.h"
 #include "queue.h"
 #include "memory.h"
+#include "srv6.h"
 #include "lib/json.h"
 #include "lib_errors.h"
 
@@ -3431,6 +3432,22 @@ int bgp_update(struct peer *peer, struct prefix *p, uint32_t addpath_id,
 				bgp_set_valid_label(&extra->label[0]);
 		}
 
+		/* Update SRv6 SID */
+		if (attr->srv6_l3vpn) {
+			extra = bgp_path_info_extra_get(pi);
+			if (sid_diff(&extra->sid[0], &attr->srv6_l3vpn->sid)) {
+				sid_copy(&extra->sid[0],
+					 &attr->srv6_l3vpn->sid);
+				extra->num_sids = 1;
+			}
+		} else if (attr->srv6_vpn) {
+			extra = bgp_path_info_extra_get(pi);
+			if (sid_diff(&extra->sid[0], &attr->srv6_vpn->sid)) {
+				sid_copy(&extra->sid[0], &attr->srv6_vpn->sid);
+				extra->num_sids = 1;
+			}
+		}
+
 #if ENABLE_BGP_VNC
 		if ((afi == AFI_IP || afi == AFI_IP6)
 		    && (safi == SAFI_UNICAST)) {
@@ -3610,6 +3627,18 @@ int bgp_update(struct peer *peer, struct prefix *p, uint32_t addpath_id,
 			bgp_set_valid_label(&extra->label[0]);
 	}
 
+	/* Update SRv6 SID */
+	if (safi == SAFI_MPLS_VPN) {
+		extra = bgp_path_info_extra_get(new);
+		if (attr->srv6_l3vpn) {
+			sid_copy(&extra->sid[0], &attr->srv6_l3vpn->sid);
+			extra->num_sids = 1;
+		} else if (attr->srv6_vpn) {
+			sid_copy(&extra->sid[0], &attr->srv6_vpn->sid);
+			extra->num_sids = 1;
+		}
+	}
+
 	/* Update Overlay Index */
 	if (afi == AFI_L2VPN) {
 		overlay_index_update(new->attr,
@@ -8994,6 +9023,15 @@ void route_vty_out_detail(struct vty *vty, struct bgp *bgp,
 			vty_out(vty, "      Remote label: %d\n", label);
 	}
 
+	/* Remote SID */
+	if (path->extra && path->extra->num_sids > 0 && safi != SAFI_EVPN) {
+		inet_ntop(AF_INET6, &path->extra->sid, buf, sizeof(buf));
+		if (json_paths)
+			json_object_string_add(json_path, "remoteSid", buf);
+		else
+			vty_out(vty, "      Remote SID: %s\n", buf);
+	}
+
 	/* Label Index */
 	if (attr->label_index != BGP_INVALID_LABEL_INDEX) {
 		if (json_paths)

bgpd/bgp_route.h

@@ -78,6 +78,9 @@ enum bgp_show_adj_route_type {
  */
 #define BGP_MAX_LABELS 2
 
+/* Maximum number of sids we can process or send with a prefix. */
+#define BGP_MAX_SIDS 6
+
 /* Error codes for handling NLRI */
 #define BGP_NLRI_PARSE_OK 0
 #define BGP_NLRI_PARSE_ERROR_PREFIX_OVERFLOW -1
@@ -118,6 +121,10 @@ struct bgp_path_info_extra {
 	uint16_t af_flags;
 #define BGP_EVPN_MACIP_TYPE_SVI_IP (1 << 0)
 
+	/* SRv6 SID(s) for SRv6-VPN */
+	struct in6_addr sid[BGP_MAX_SIDS];
+	uint32_t num_sids;
+
 #if ENABLE_BGP_VNC
 	union {
 

bgpd/rfapi/rfapi_vty.c

@@ -431,6 +431,14 @@ void rfapi_vty_out_vncinfo(struct vty *vty, struct prefix *p,
 		else
 			vty_out(vty, " label=%u",
 				decode_label(&bpi->extra->label[0]));
+
+		if (bpi->extra->num_sids) {
+			char buf[BUFSIZ];
+
+			vty_out(vty, " sid=%s",
+				inet_ntop(AF_INET6, &bpi->extra->sid[0], buf,
+					  sizeof(buf)));
+		}
 	}
 
 	if (!rfapiGetVncLifetime(bpi->attr, &lifetime)) {

lib/srv6.c

@@ -0,0 +1,116 @@
+/*
+ * SRv6 definitions
+ * Copyright (C) 2020  Hiroki Shirokura, LINE Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "srv6.h"
+#include "log.h"
+
+const char *seg6local_action2str(uint32_t action)
+{
+	switch (action) {
+	case ZEBRA_SEG6_LOCAL_ACTION_END:
+		return "End";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_X:
+		return "End.X";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_T:
+		return "End.T";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_DX2:
+		return "End.DX2";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_DX6:
+		return "End.DX6";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_DX4:
+		return "End.DX4";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_DT6:
+		return "End.DT6";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_DT4:
+		return "End.DT4";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_B6:
+		return "End.B6";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_B6_ENCAP:
+		return "End.B6.Encap";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_BM:
+		return "End.BM";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_S:
+		return "End.S";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_AS:
+		return "End.AS";
+	case ZEBRA_SEG6_LOCAL_ACTION_END_AM:
+		return "End.AM";
+	case ZEBRA_SEG6_LOCAL_ACTION_UNSPEC:
+		return "unspec";
+	default:
+		return "unknown";
+	}
+}
+
+int snprintf_seg6_segs(char *str,
+		size_t size, const struct seg6_segs *segs)
+{
+	str[0] = '\0';
+	for (size_t i = 0; i < segs->num_segs; i++) {
+		char addr[INET6_ADDRSTRLEN];
+		bool not_last = (i + 1) < segs->num_segs;
+
+		inet_ntop(AF_INET6, &segs->segs[i], addr, sizeof(addr));
+		strlcat(str, addr, size);
+		strlcat(str, not_last ? "," : "", size);
+	}
+	return strlen(str);
+}
+
+const char *seg6local_context2str(char *str, size_t size,
+		struct seg6local_context *ctx, uint32_t action)
+{
+	char b0[128];
+
+	switch (action) {
+
+	case ZEBRA_SEG6_LOCAL_ACTION_END:
+		snprintf(str, size, "USP");
+		return str;
+
+	case ZEBRA_SEG6_LOCAL_ACTION_END_X:
+	case ZEBRA_SEG6_LOCAL_ACTION_END_DX6:
+		inet_ntop(AF_INET6, &ctx->nh6, b0, 128);
+		snprintf(str, size, "nh6 %s", b0);
+		return str;
+
+	case ZEBRA_SEG6_LOCAL_ACTION_END_DX4:
+		inet_ntop(AF_INET, &ctx->nh4, b0, 128);
+		snprintf(str, size, "nh4 %s", b0);
+		return str;
+
+	case ZEBRA_SEG6_LOCAL_ACTION_END_T:
+	case ZEBRA_SEG6_LOCAL_ACTION_END_DT6:
+	case ZEBRA_SEG6_LOCAL_ACTION_END_DT4:
+		snprintf(str, size, "table %u", ctx->table);
+		return str;
+
+	case ZEBRA_SEG6_LOCAL_ACTION_END_DX2:
+	case ZEBRA_SEG6_LOCAL_ACTION_END_B6:
+	case ZEBRA_SEG6_LOCAL_ACTION_END_B6_ENCAP:
+	case ZEBRA_SEG6_LOCAL_ACTION_END_BM:
+	case ZEBRA_SEG6_LOCAL_ACTION_END_S:
+	case ZEBRA_SEG6_LOCAL_ACTION_END_AS:
+	case ZEBRA_SEG6_LOCAL_ACTION_END_AM:
+	case ZEBRA_SEG6_LOCAL_ACTION_UNSPEC:
+	default:
+		snprintf(str, size, "unknown(%s)", __func__);
+		return str;
+	}
+}